Separating and recovering specified cells in a culture solution is very important technique in biological and medical analyses. Normally, when cells are sorted according to differences in their specific gravity, the sorting can be carried out by a velocity sedimentation method. When, however, differences in cells such as distinguishing unsensitized cells from sensitized cells are hardly present, it is necessary to sort the cells one by one based on information obtained either by staining with a fluorescent antibody or by visual observation. This technique includes, for example, cell sorters. Each individual, fluorescently stained cell is isolated into a liquid drop to which an electric charge is imparted. Based on the presence or absence of fluorescence from the cell in the liquid drop or based on the amount of scattering light, a high electric field is applied in an arbitrary direction perpendicular to the direction of dropping while the drop is falling to thereby control the direction of dropping of the liquid drop. In this way, the cells are separately recovered in a plurality of containers placed underneath. The details of this technique are reported in “Methods Enzymol, Vol. 151, pp. 150 to 165 (1987)” by Kamarck. M. E.